Virtually no information exists regarding the developmental program of RNA and protein synthesis, and its utilisation in sea urchin oogenesis. RNA and protein synthesized during oogenesis is used to direct the growth and differentiation of the oocyte, and the formation of the program for early embryogenesis. This research program is designed to investigate the relationship between gene function in oogenesis, formation of the mature egg, and the events of early embryonic development. The aims are threefold: (1) Using isolated oocytes of different stages, the program of stage-specific synthesis of protein and of rRNA, 4S RNA, 5S RNA and mRNA will be determined, using high resolution gel electrophoresis, and cell-free translation of mRNA. (2) Differential utilization of oocyte mRNA will be studied. Both quantitative and qualitative differences in the class of mRNA used for protein synthesis in the oocyte, and the mRNA selectively sequestered in the formation of the maternal mRNA program will be examined. mRNA from oocyte polysomes (engaged in protein synthesis) and from the subribosomal compartment (the site of maternal mRNA storage) will be compared by gel electrophoresis and by cell-free translation. The temporal sequence of synthesis and utilisation of particular identifiable maternal mRNAs (e.g., tubulin and histone mRNA) will be carefully studied. (3) The question of selective, qualitative vs. non-selective, quantitative recruitment of maternal following fertilization will be investigated. The recruitment of specific maternal mRNAs from the subribosomal to the polysomal compartment following fertilization will be monitored, using the cell-free translation assay. Furthermore, the relationship between post-fertilization cytoplasmic adenylation of of maternal mRNA and the utilization of specific poly (A) plus and poly (A) minus maternal mRNAs will be studied, using the translation assay. It is anticipated that these different and complementary approaches will contribute a substantial amount of new information about the molecular events of the developmental program of oocyte growth, differentiation, and the formation and use of the maternal mRNA program.